Development characteristics and sedimentary control of mineable coal seams in Yongxia coalfield

In order to investigate the development characteristics of mineable coal seam of the Yongxia coalfield,this paper systematically analyzes previous geological data of the study area.The results show that the mineable coal seams in study area are 二₂ coal seam of the Shanxi formation and 三₂ coal seam and 三₄ coal seam of the lower Shihezi formation.二₂ coal seam is the main mineable coal seam.It is minable in most areas with single and stable structures and the average thickness is 2.67 m.The others are locally mineable, they are generally 1.08-1.46 m thick, poorly stable, and have complex structure with 1 layer to multi-layer gangue.The minable coal seams are formed in two major sedimentary systems, which are the tidal-lagoon sedimentary system below 二₂ seam coal and the delta sedimentary system above 二₂ coal seam.The thickness and structure of coal seams are obviously affected by persistent development time and basement morphology of peat marshes, debris supply, and river scouring.